The present invention relates to graphene reinforced materials and related methods of manufacture.
Graphene is an individual layer of carbon having a hexagonal bonding structure in a one-atom thick sheet. Graphene is known to exhibit low densities (<0.77 mg/m2) and a high tensile strength (>130,000 MPa). The tensile strength of graphene is greater than that of carbon steel (850 MPa), diamond (2,800 MPa), aramid (3,700) and carbon fiber (6000 MPa). In view of the desirable mechanical properties of graphene, a reliable technology for the scalable production of graphene articles is desired.
One known technique for graphene production includes mechanical exfoliation of graphite crystals. However, graphene produced by this method yields unconnected micrometer-sized graphene crystals in a powder form which has certain limitations in material reinforcement applications. Another known technique includes chemical vapor deposition at low pressures. According to this method, a metal substrate is annealed in a reducing atmosphere. After annealing, the metal substrate is exposed to a carbon source in a low pressure reactor to synthesize graphene. A variety of organic gases and solids can be used as the carbon source for graphene growth, with methane gas being a widely used precursor. However, the metal substrate can be difficult to feed into the low pressure reactor, accompanied by severe evaporation of the metal and the requirement of a vacuum system compatible with flammable precursor gases.